Internal combustion engine



Oct. 4, POLSTQN 1,881,294

INTERNAL COMBUSTION ENGINE Filed Aug. 21 1930 2. Sheets-Sheet 1 jam/4 Oct. 4, 1932. POLSTON 1,881,294

INTERNAL COMBUSTION ENGINE Filed Aug. 21, 1930 2 Sheets-Sheet 2 7 17 /6 ,1? lfy q [9 Z9 {.9

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Patented Oct 4 1932 UNITED STATES MAB/DELL 1). POLSTO1\T, OF OVIEDO, FLORIDA INTERNAL COMBUSTION ENGINE- Application filed August 21, 1930. Serial 110.476,!)16.

The invention relates to improvements in internal combustion engines and has particular reference to the construction of the cylinder block whereby the cylinders are removably and replaceably secured in the block, the block having spaced upper lower walls provided with openings to receive the cylinders, and the walls of the opening in the lower wall of the block being internally threaded to engage external threads on the cylinder sleeves so that the cylinder sleeves may be removed and replaced as desired when the sleeves and pistons become worn, thus dispensing with the necessity of reboring the cylinders and installing oversized pistons as is now the usual custom periodically in internal combustion engines.

Furthermore, by this construction another object is gained in that the cylinder sleeves are directly in contact with the cooling medium, usually water, employed in internal combustion engines and danger of cracking the cylinders because of unequal expansion and contraction is avoided.

A further object of the invention is the provision of means by which the fuel ducts to the cylinders are led through the cooling system to insure a proper temperature for the fuel for most efficient operation of the engine.

The invention will be described in detail hereinafter and will be found illustrated in the accompanying drawings in which Figure 1 is a vertical sectional view of an internal combustion engine constructed in accordance with the invention,

Figure 2 is a fragmentary longitudinal vertical section of a four cylinder engine block and head,

Figure 3 is a fragmentary sectional View on a plane through the intake duct, and

Figure 4 is a similar view on a plane taken through the exhaust duct.

In the drawings similar reference characters are used to designate corresponding parts in all the views.

The improved internal, combustion engine includes an engine block 1 having spaced top and bottom walls 2 and 3, respectively, and provided with alined openings 4 and 5, respectively to receive sleeves 6 that comprise the engine cylinders. The upper ends of the sleeves 6 are provided with circumferential flanges 7 that engage in circumferential grooves '8 in the top wall 2, while the lower ends of the sleeves 6 are eX-teriorly threaded as shown at 9 to engage the interiorly threaded walls of the openings 5, the bottom wall 3 being provided with upwardly extending flanges 10 to reinforce the walls at the openlngs 5 and lncrease the bearing surface for G the sleeves 6. The upper edges of the sleeves 6 are provided with notches orother well known means for engagementby a spanner wrench or the like for screwing and unscrewing the sleeves in placing them in position or removing them therefrom, said notches being designated 11. I

The engine head is indicated at 12 and is of the usual hollow construction to provide 'ZL-COIldlllt for the usual cooling medlum, and

the bottom wall 13 of said head is provided with conical recesses 14 forming the com pressed chambers for the engine cylinders, the walls 15 of said conical recesses 14 having their upper smaller ends integral with the upper wall 16 of the head and provided with openings 17 to receive the ignition devices 18, shown as spark plugs, of conventional type. The conical walls 15 are provided with ports 19 for the intake and exhaust valves 20 and 21, 22 designating pipes or conduits leading from said openings 19 through space in the head for the cooling medium, this arrangement insuring that the fuel supplied to the cylinders will be properly tempered for the most satisfactory operation of the engine.

The stems of the valves 20 and 21, designated 23, slidably engage the inclined bearings 24, 25 indicating the rocker arms for actuating the valves that are in turn actuated by the tappets 26, 27 indicating the cam shaft for actuating the tappets 26.

Because of the construction relating to the engine cylinders consisting of the sleeves 6 that are removably mounted in the engine block, as hereinbefore described, said sleeves being exposed directly to the cooling medium in the space enclosed within the block, the engine cylinders are maintained cool at all times, and by the construction providing the ,2 i H I 1,881,294;

removable sleeves, it is apparent that the sleeves may be removed and replaced for repair, and to obviate the necessity of reboring that is necessary in internal combustion en- 5 gines from time to time, as it is practical to replace the worn cylinder sleeves with new ones and the pistons also, and this replacement is quickly and economically accomplished.

By providing the conical recesses 14 and providing the ignition device in the apices of the recesses provision is made by which the full downward force of the explosion is utilized, centered over the piston in each cylinder, this giving more power to the quantity of fuel consumed and eliminating spark or gas knocks on heavy pulling. Furthermore by removing the spark plugs from their seats carbon in the engine pistons may be easily removed and the valves ground without removing the engine head.

Also the block and cylinders being made separately makes the cost of production and assembling the motor extremely reasonable,

as the block may be made of cheaper material than now employed in making the casing and cylinder walls in one piece, and as the cylinders are surrounded by water they are maintained cool, this giving better compression,

the most power and economy in the use of lubricating oil.

Also as the water connection between the cylinder block and head is arranged in only one position, furthest removed from the nipples for connection to the radiator or complete circulation of the water is assured and that it will be kept cooler than in engines as at present constructed even to the exclusion of an air circulating fan.

4o By bevelling the inner walls of the cylinder at their lower ends, it will be apparent that rings and pistons may be readily inserted in event of repair.

What is claimed is v 45 An engine casing, comprising an engine block having spaced top and bottom walls provided with alined openings, the wall of the opening in the top wall having a circumferential groove communicating with the open- 50 ing, the wall of the opening in the bottom wall being threaded, a tubular member removably mounted in said openings and provided with an outwardly directed circumferential flange on its upper end seating in said groove, and

: its lower end threaded and engaging the threiaded wall of the opening in the bottom wal ' In testimony whereof I aflix my signature.

MARDELL D. POLSTON. 

